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      1 #!/usr/bin/env python
      2 # A tool to parse ASTMatchers.h and update the documentation in
      3 # ../LibASTMatchersReference.html automatically. Run from the
      4 # directory in which this file is located to update the docs.
      5 
      6 import collections
      7 import re
      8 import urllib2
      9 
     10 MATCHERS_FILE = '../../include/clang/ASTMatchers/ASTMatchers.h'
     11 
     12 # Each matcher is documented in one row of the form:
     13 #   result | name | argA
     14 # The subsequent row contains the documentation and is hidden by default,
     15 # becoming visible via javascript when the user clicks the matcher name.
     16 TD_TEMPLATE="""
     17 <tr><td>%(result)s</td><td class="name" onclick="toggle('%(id)s')"><a name="%(id)sAnchor">%(name)s</a></td><td>%(args)s</td></tr>
     18 <tr><td colspan="4" class="doc" id="%(id)s"><pre>%(comment)s</pre></td></tr>
     19 """
     20 
     21 # We categorize the matchers into these three categories in the reference:
     22 node_matchers = {}
     23 narrowing_matchers = {}
     24 traversal_matchers = {}
     25 
     26 # We output multiple rows per matcher if the matcher can be used on multiple
     27 # node types. Thus, we need a new id per row to control the documentation
     28 # pop-up. ids[name] keeps track of those ids.
     29 ids = collections.defaultdict(int)
     30 
     31 # Cache for doxygen urls we have already verified.
     32 doxygen_probes = {}
     33 
     34 def esc(text):
     35   """Escape any html in the given text."""
     36   text = re.sub(r'&', '&amp;', text)
     37   text = re.sub(r'<', '&lt;', text)
     38   text = re.sub(r'>', '&gt;', text)
     39   def link_if_exists(m):
     40     name = m.group(1)
     41     url = 'http://clang.llvm.org/doxygen/classclang_1_1%s.html' % name
     42     if url not in doxygen_probes:
     43       try:
     44         print 'Probing %s...' % url
     45         urllib2.urlopen(url)
     46         doxygen_probes[url] = True
     47       except:
     48         doxygen_probes[url] = False
     49     if doxygen_probes[url]:
     50       return r'Matcher&lt;<a href="%s">%s</a>&gt;' % (url, name)
     51     else:
     52       return m.group(0)
     53   text = re.sub(
     54     r'Matcher&lt;([^\*&]+)&gt;', link_if_exists, text)
     55   return text
     56 
     57 def extract_result_types(comment):
     58   """Extracts a list of result types from the given comment.
     59 
     60      We allow annotations in the comment of the matcher to specify what
     61      nodes a matcher can match on. Those comments have the form:
     62        Usable as: Any Matcher | (Matcher<T1>[, Matcher<t2>[, ...]])
     63 
     64      Returns ['*'] in case of 'Any Matcher', or ['T1', 'T2', ...].
     65      Returns the empty list if no 'Usable as' specification could be
     66      parsed.
     67   """
     68   result_types = []
     69   m = re.search(r'Usable as: Any Matcher[\s\n]*$', comment, re.S)
     70   if m:
     71     return ['*']
     72   while True:
     73     m = re.match(r'^(.*)Matcher<([^>]+)>\s*,?[\s\n]*$', comment, re.S)
     74     if not m:
     75       if re.search(r'Usable as:\s*$', comment):
     76         return result_types
     77       else:
     78         return None
     79     result_types += [m.group(2)]
     80     comment = m.group(1)
     81 
     82 def strip_doxygen(comment):
     83   """Returns the given comment without \-escaped words."""
     84   # If there is only a doxygen keyword in the line, delete the whole line.
     85   comment = re.sub(r'^\\[^\s]+\n', r'', comment, flags=re.M)
     86   
     87   # If there is a doxygen \see command, change the \see prefix into "See also:".
     88   # FIXME: it would be better to turn this into a link to the target instead.
     89   comment = re.sub(r'\\see', r'See also:', comment)
     90   
     91   # Delete the doxygen command and the following whitespace.
     92   comment = re.sub(r'\\[^\s]+\s+', r'', comment)
     93   return comment
     94 
     95 def unify_arguments(args):
     96   """Gets rid of anything the user doesn't care about in the argument list."""
     97   args = re.sub(r'internal::', r'', args)
     98   args = re.sub(r'const\s+(.*)&', r'\1 ', args)
     99   args = re.sub(r'&', r' ', args)
    100   args = re.sub(r'(^|\s)M\d?(\s)', r'\1Matcher<*>\2', args)
    101   return args
    102 
    103 def add_matcher(result_type, name, args, comment, is_dyncast=False):
    104   """Adds a matcher to one of our categories."""
    105   if name == 'id':
    106      # FIXME: Figure out whether we want to support the 'id' matcher.
    107      return
    108   matcher_id = '%s%d' % (name, ids[name])
    109   ids[name] += 1
    110   args = unify_arguments(args)
    111   matcher_html = TD_TEMPLATE % {
    112     'result': esc('Matcher<%s>' % result_type),
    113     'name': name,
    114     'args': esc(args),
    115     'comment': esc(strip_doxygen(comment)),
    116     'id': matcher_id,
    117   }
    118   if is_dyncast:
    119     node_matchers[result_type + name] = matcher_html
    120   # Use a heuristic to figure out whether a matcher is a narrowing or
    121   # traversal matcher. By default, matchers that take other matchers as
    122   # arguments (and are not node matchers) do traversal. We specifically
    123   # exclude known narrowing matchers that also take other matchers as
    124   # arguments.
    125   elif ('Matcher<' not in args or
    126         name in ['allOf', 'anyOf', 'anything', 'unless']):
    127     narrowing_matchers[result_type + name + esc(args)] = matcher_html
    128   else:
    129     traversal_matchers[result_type + name + esc(args)] = matcher_html
    130 
    131 def act_on_decl(declaration, comment, allowed_types):
    132   """Parse the matcher out of the given declaration and comment.
    133 
    134      If 'allowed_types' is set, it contains a list of node types the matcher
    135      can match on, as extracted from the static type asserts in the matcher
    136      definition.
    137   """
    138   if declaration.strip():
    139     # Node matchers are defined by writing:
    140     #   VariadicDynCastAllOfMatcher<ResultType, ArgumentType> name;
    141     m = re.match(r""".*Variadic(?:DynCast)?AllOfMatcher\s*<
    142                        \s*([^\s,]+)\s*(?:,
    143                        \s*([^\s>]+)\s*)?>
    144                        \s*([^\s;]+)\s*;\s*$""", declaration, flags=re.X)
    145     if m:
    146       result, inner, name = m.groups()
    147       if not inner:
    148         inner = result
    149       add_matcher(result, name, 'Matcher<%s>...' % inner,
    150                   comment, is_dyncast=True)
    151       return
    152 
    153     # Parse the various matcher definition macros.
    154     m = re.match(""".*AST_TYPE_MATCHER\(
    155                        \s*([^\s,]+\s*),
    156                        \s*([^\s,]+\s*)
    157                      \)\s*;\s*$""", declaration, flags=re.X)
    158     if m:
    159       inner, name = m.groups()
    160       add_matcher('Type', name, 'Matcher<%s>...' % inner,
    161                   comment, is_dyncast=True)
    162       # FIXME: re-enable once we have implemented casting on the TypeLoc
    163       # hierarchy.
    164       # add_matcher('TypeLoc', '%sLoc' % name, 'Matcher<%sLoc>...' % inner,
    165       #             comment, is_dyncast=True)
    166       return
    167 
    168     m = re.match(""".*AST_TYPE(LOC)?_TRAVERSE_MATCHER\(
    169                        \s*([^\s,]+\s*),
    170                        \s*(?:[^\s,]+\s*),
    171                        \s*AST_POLYMORPHIC_SUPPORTED_TYPES\(([^)]*)\)
    172                      \)\s*;\s*$""", declaration, flags=re.X)
    173     if m:
    174       loc, name, results = m.groups()[0:3]
    175       result_types = [r.strip() for r in results.split(',')]
    176 
    177       comment_result_types = extract_result_types(comment)
    178       if (comment_result_types and
    179           sorted(result_types) != sorted(comment_result_types)):
    180         raise Exception('Inconsistent documentation for: %s' % name)
    181       for result_type in result_types:
    182         add_matcher(result_type, name, 'Matcher<Type>', comment)
    183         if loc:
    184           add_matcher('%sLoc' % result_type, '%sLoc' % name, 'Matcher<TypeLoc>',
    185                       comment)
    186       return
    187 
    188     m = re.match(r"""^\s*AST_POLYMORPHIC_MATCHER(_P)?(.?)(?:_OVERLOAD)?\(
    189                           \s*([^\s,]+)\s*,
    190                           \s*AST_POLYMORPHIC_SUPPORTED_TYPES\(([^)]*)\)
    191                        (?:,\s*([^\s,]+)\s*
    192                           ,\s*([^\s,]+)\s*)?
    193                        (?:,\s*([^\s,]+)\s*
    194                           ,\s*([^\s,]+)\s*)?
    195                        (?:,\s*\d+\s*)?
    196                       \)\s*{\s*$""", declaration, flags=re.X)
    197 
    198     if m:
    199       p, n, name, results = m.groups()[0:4]
    200       args = m.groups()[4:]
    201       result_types = [r.strip() for r in results.split(',')]
    202       if allowed_types and allowed_types != result_types:
    203         raise Exception('Inconsistent documentation for: %s' % name)
    204       if n not in ['', '2']:
    205         raise Exception('Cannot parse "%s"' % declaration)
    206       args = ', '.join('%s %s' % (args[i], args[i+1])
    207                        for i in range(0, len(args), 2) if args[i])
    208       for result_type in result_types:
    209         add_matcher(result_type, name, args, comment)
    210       return
    211 
    212     m = re.match(r"""^\s*AST_MATCHER_FUNCTION(_P)?(.?)(?:_OVERLOAD)?\(
    213                        (?:\s*([^\s,]+)\s*,)?
    214                           \s*([^\s,]+)\s*
    215                        (?:,\s*([^\s,]+)\s*
    216                           ,\s*([^\s,]+)\s*)?
    217                        (?:,\s*([^\s,]+)\s*
    218                           ,\s*([^\s,]+)\s*)?
    219                        (?:,\s*\d+\s*)?
    220                       \)\s*{\s*$""", declaration, flags=re.X)
    221     if m:
    222       p, n, result, name = m.groups()[0:4]
    223       args = m.groups()[4:]
    224       if n not in ['', '2']:
    225         raise Exception('Cannot parse "%s"' % declaration)
    226       args = ', '.join('%s %s' % (args[i], args[i+1])
    227                        for i in range(0, len(args), 2) if args[i])
    228       add_matcher(result, name, args, comment)
    229       return
    230 
    231     m = re.match(r"""^\s*AST_MATCHER(_P)?(.?)(?:_OVERLOAD)?\(
    232                        (?:\s*([^\s,]+)\s*,)?
    233                           \s*([^\s,]+)\s*
    234                        (?:,\s*([^,]+)\s*
    235                           ,\s*([^\s,]+)\s*)?
    236                        (?:,\s*([^\s,]+)\s*
    237                           ,\s*([^\s,]+)\s*)?
    238                        (?:,\s*\d+\s*)?
    239                       \)\s*{\s*$""", declaration, flags=re.X)
    240     if m:
    241       p, n, result, name = m.groups()[0:4]
    242       args = m.groups()[4:]
    243       if not result:
    244         if not allowed_types:
    245           raise Exception('Did not find allowed result types for: %s' % name)
    246         result_types = allowed_types
    247       else:
    248         result_types = [result]
    249       if n not in ['', '2']:
    250         raise Exception('Cannot parse "%s"' % declaration)
    251       args = ', '.join('%s %s' % (args[i], args[i+1])
    252                        for i in range(0, len(args), 2) if args[i])
    253       for result_type in result_types:
    254         add_matcher(result_type, name, args, comment)
    255       return
    256 
    257     # Parse ArgumentAdapting matchers.
    258     m = re.match(
    259         r"""^.*ArgumentAdaptingMatcherFunc<.*>\s*(?:LLVM_ATTRIBUTE_UNUSED\s*)
    260               ([a-zA-Z]*)\s*=\s*{};$""",
    261         declaration, flags=re.X)
    262     if m:
    263       name = m.groups()[0]
    264       add_matcher('*', name, 'Matcher<*>', comment)
    265       return
    266 
    267     # Parse Variadic functions.
    268     m = re.match(
    269         r"""^.*internal::VariadicFunction\s*<\s*([^,]+),\s*([^,]+),\s*[^>]+>\s*
    270               ([a-zA-Z]*)\s*=\s*{.*};$""",
    271         declaration, flags=re.X)
    272     if m:
    273       result, arg, name = m.groups()[:3]
    274       add_matcher(result, name, '%s, ..., %s' % (arg, arg), comment)
    275       return
    276 
    277     # Parse Variadic operator matchers.
    278     m = re.match(
    279         r"""^.*VariadicOperatorMatcherFunc\s*<\s*([^,]+),\s*([^\s>]+)\s*>\s*
    280               ([a-zA-Z]*)\s*=\s*{.*};$""",
    281         declaration, flags=re.X)
    282     if m:
    283       min_args, max_args, name = m.groups()[:3]
    284       if max_args == '1':
    285         add_matcher('*', name, 'Matcher<*>', comment)
    286         return
    287       elif max_args == 'UINT_MAX':
    288         add_matcher('*', name, 'Matcher<*>, ..., Matcher<*>', comment)
    289         return
    290 
    291 
    292     # Parse free standing matcher functions, like:
    293     #   Matcher<ResultType> Name(Matcher<ArgumentType> InnerMatcher) {
    294     m = re.match(r"""^\s*(.*)\s+
    295                      ([^\s\(]+)\s*\(
    296                      (.*)
    297                      \)\s*{""", declaration, re.X)
    298     if m:
    299       result, name, args = m.groups()
    300       args = ', '.join(p.strip() for p in args.split(','))
    301       m = re.match(r'.*\s+internal::(Bindable)?Matcher<([^>]+)>$', result)
    302       if m:
    303         result_types = [m.group(2)]
    304       else:
    305         result_types = extract_result_types(comment)
    306       if not result_types:
    307         if not comment:
    308           # Only overloads don't have their own doxygen comments; ignore those.
    309           print 'Ignoring "%s"' % name
    310         else:
    311           print 'Cannot determine result type for "%s"' % name
    312       else:
    313         for result_type in result_types:
    314           add_matcher(result_type, name, args, comment)
    315     else:
    316       print '*** Unparsable: "' + declaration + '" ***'
    317 
    318 def sort_table(matcher_type, matcher_map):
    319   """Returns the sorted html table for the given row map."""
    320   table = ''
    321   for key in sorted(matcher_map.keys()):
    322     table += matcher_map[key] + '\n'
    323   return ('<!-- START_%(type)s_MATCHERS -->\n' +
    324           '%(table)s' + 
    325           '<!--END_%(type)s_MATCHERS -->') % {
    326     'type': matcher_type,
    327     'table': table,
    328   }
    329 
    330 # Parse the ast matchers.
    331 # We alternate between two modes:
    332 # body = True: We parse the definition of a matcher. We need
    333 #   to parse the full definition before adding a matcher, as the
    334 #   definition might contain static asserts that specify the result
    335 #   type.
    336 # body = False: We parse the comments and declaration of the matcher.
    337 comment = ''
    338 declaration = ''
    339 allowed_types = []
    340 body = False
    341 for line in open(MATCHERS_FILE).read().splitlines():
    342   if body:
    343     if line.strip() and line[0] == '}':
    344       if declaration:
    345         act_on_decl(declaration, comment, allowed_types)
    346         comment = ''
    347         declaration = ''
    348         allowed_types = []
    349       body = False
    350     else:
    351       m = re.search(r'is_base_of<([^,]+), NodeType>', line)
    352       if m and m.group(1):
    353         allowed_types += [m.group(1)]
    354     continue
    355   if line.strip() and line.lstrip()[0] == '/':
    356     comment += re.sub(r'/+\s?', '', line) + '\n'
    357   else:
    358     declaration += ' ' + line
    359     if ((not line.strip()) or 
    360         line.rstrip()[-1] == ';' or
    361         (line.rstrip()[-1] == '{' and line.rstrip()[-3:] != '= {')):
    362       if line.strip() and line.rstrip()[-1] == '{':
    363         body = True
    364       else:
    365         act_on_decl(declaration, comment, allowed_types)
    366         comment = ''
    367         declaration = ''
    368         allowed_types = []
    369 
    370 node_matcher_table = sort_table('DECL', node_matchers)
    371 narrowing_matcher_table = sort_table('NARROWING', narrowing_matchers)
    372 traversal_matcher_table = sort_table('TRAVERSAL', traversal_matchers)
    373 
    374 reference = open('../LibASTMatchersReference.html').read()
    375 reference = re.sub(r'<!-- START_DECL_MATCHERS.*END_DECL_MATCHERS -->',
    376                    node_matcher_table, reference, flags=re.S)
    377 reference = re.sub(r'<!-- START_NARROWING_MATCHERS.*END_NARROWING_MATCHERS -->',
    378                    narrowing_matcher_table, reference, flags=re.S)
    379 reference = re.sub(r'<!-- START_TRAVERSAL_MATCHERS.*END_TRAVERSAL_MATCHERS -->',
    380                    traversal_matcher_table, reference, flags=re.S)
    381 
    382 with open('../LibASTMatchersReference.html', 'wb') as output:
    383   output.write(reference)
    384 
    385